hypolipidemic effect of curcumin in hyper-cholesterolemic rats

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Hypolipidemic effect of curcumin in hyper-cholesterolemic rats Samy A. Hussein, Yakout A. El-Senosi, Mohammed R. Ragab, Mohammed M.F. Hammad Department of Biochemistry, Faculty of Veterinary Medicine, Benha University. A B S T R A C T Hypercholesterolemia is one of the most important risk factors for atherosclerosis and subsequent cardiovascular disease. In the present study, the therapeutic effect of curcumin (CUR) administration on serum lipid profile, apolipoprotein A (apo A), apolipoprotein B (apo B), Lipoprotein a Lp (a), homocysteine and endotheline-1 (ET-1) in high cholesterol diet-induced hypercholesterolemia in rats have been evaluated. This study was carried out on 60 male rats. The rats were divided into four equal groups of 15 rats each. Group Ι :( Control group): rats fed on normal diet. Group Π: Rats fed with hypercholesterolemic diet (HCD) [4% cholesterol (w/w) and 1% cholic acid] and received no drug all over the period of the experiment. Group III: Rats fed with HCD + administrated with curcumin (200 mg/kg, body weight/day orally) after two weeks from the onset of the experiment (induction of hypercholesterolemia).Group IV: Rats fed with normal diet + administrated with curcumin (200 mg/kg, body weight/day orally) after two weeks from the onset of the experiment. Blood samples were collected from all animal groups three times at 2, 4 and 6 weeks from the onset of treatment with curcumin. The obtained results showed that, cholesterol-induced hypercholesterolemia caused a marked increase in serum total cholesterol, triacylglycerols, LDL-C, VLDL-C, phospholipids, lipoprotein A, Apo B, endothelin-1 and homocysteine. On the other hand, a significant decrease in serum HDL–C and Apo A were observed in high cholesterol diet-induced hypercholesterolemia in rats. Treatment with curcumin to high cholesterol diet-induced hypercholesterolemia rats lowered serum total cholesterol, triacylglycerols, LDL-C, VLDL-C, phospholipid, endothelin-1 and homocysteine concentration, in addition to, increasing HDL-C and Apo A. These results suggest that, curcumin may be effective in controlling cholesterolemic status and improving dyslipidemia and has the potential in reducing cardiovascular complications due to hypercholesterolemia.

Keywords: Curcumin; Hypercholesterolemia; lipid profile; Endothelin-1; Homocysteine

(http://www.bvmj.bu.edu.eg) (BVMJ‐27(2): 277‐289 , 2014)

1. INTRODUCTION

merican heart association (AHA) defined hyperlipidemia is a high level of fats in the blood. These fats, called

lipids include cholesterol and triglycerides. There are different types of hyperlipidemia depending on which lipid levels are high in the blood (Jain et al., 2007). Elevated levels of plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triacylglycerol (TAG) as well as reduced levels of plasma high density lipoprotein

cholesterol (HDL-C) are often associated with an increased risk of coronary heart disease (Smith et al., 2004). Hypercholesterolemia is a condition characterized by very high levels of cholesterol in the blood. Cholesterol is a waxy, fat-like substance that is produced in the body and obtained from foods that come from animals (particularly egg yolks, meat, poultry, fish, and dairy products). The body needs this substance to build cell membranes,

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make certain hormones, and produce compounds that aid in fat digestion. Recently, hypercholesterolemia has been associated with enhanced oxidative stress related to increased lipid peroxidation. Increased generation of oxidized LDL is a major factor in the vascular damage associated with high cholesterol levels. Hence, the inhibition of oxidative stress under hypercholesterolemic conditions is considered to be an important therapeutic approach and efforts have been made to identify the antioxidative functions of various medicinal plants (Adaramoye et al., 2008). Hypercholesterolemia is one of the most important risk factors for atherosclerosis and subsequent cardiovascular disease (Steinberg, 2002). Hypercholesterolemia and Hyperlipidemia has been ranked as one of the greatest risk factors contributing to the prevalence and severity of coronary heart diseases. In developing countries, the incidence of cardiovascular disease is increasing alarmingly especially; India is on the verge of a cardiovascular epidemic (Okrainec et al., 2004). Feeding animals with cholesterol has often been used to elevate serum or tissue cholesterol levels to study the etiology of hypercholesterolemia-related metabolic disturbances (Bocan, 1998). Exogenous hypercholesterolemia causes fat deposition in the liver and depletion of the hepatocyte population; it can also cause malfunctioning of the liver, which apparently follows micro vesicular stenosis due to the intracellular accumulation of lipids (Assy et al., 2000). In addition, feeding cholesterol-rich diets induces free radical production (ROS), followed by oxidative stress and hypercholesterolemia (Bulur et al., 1995). Curcumin is the most active component of turmeric, which turmeric contains chemical constituents known as the curcuminoids, which composed of curcumin (curcumin I), de-methoxy-curcumin (curcumin II) and bis-demethoxycurcumin (curcumin III). Commercial curcumin contains curcumin I

(~77%), curcumin II (~17%) and curcumin III (~3%) as its major components (Aggarwal et al., 2007). Also, Curcumin exhibits antioxidant, anti-inflammatory and anti-tumor properties (Joe et al., 2004). Moreover, curcumin regulates the expression of genes involved in energy metabolism and lipid accumulation, decreasing the level of intracellular lipids (Alappat and Awad, 2010). Accordingly, the purpose of the present study was to investigate the effect of curcumin against high cholesterol diet induced hypercholesterolemia in rats. Also, to determine whether curcumin when administered to hypercholesterolemic induced-rats beneficial for prevention and treatment of hypercholesterolemia complications.

2. MATERIALS AND METHODS

2.1. Experimental animals:

Sixty male albino rats, 12-16 weeks old and average body weight 180-220 g were used in the experimental investigation of this study. Rats were obtained from Laboratory Animals Research Center, Faculty of Veterinary Medicine, Moshtohor, Benha University. Animals were housed in separate metal cages, fresh and clean drinking water was supplied ad-libitum. Rats were kept at constant environmental and nutritional conditions throughout the period of experiment. The animals were left 14 days for acclimatization before the beginning of the experiment.

2.2. Curcumin:

Curcumin (purity ~99%) was manufactured by Fluka Co. for chemicals and purchased from El-Gomhouria Co. for Trading Chemicals Medicines and Medical Appliances, Egypt. Curcumin was freshly prepared by dissolved in 7% DMSO solution then complete to 100 ml distilled water, and was administered every day orally at a dose

Beneficial effect of flaxseed oil on lipid metabolism in high cholesterol diet fed rats

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of (200 mg/kg b.wt.) for 42 days (Aggrewal et al., 2003).

2.3. Induction of Hypercholesterolemia:

Hypercholesterolemia was induced in rat by feeding high cholesterol diet [4% cholesterol (w/w) and 1% cholic acid (w/w)] for 8-weeks (Kamesh and Sumathi, 2012).

2.4. Design of the experimental work:

Rats were randomly divided into four main equal groups, 15 rats each, placed in individual cages and classified as follow:- Group 1: Control Normal group: Rats fed an ordinary diet only without any treatment during the entire experimental period of 8-weeks. Group 2: High cholesterol diet (HCD) group: Rats fed with hypercholesterolemic diet (HCD) [4% cholesterol (w/w) and 1% cholic acid] and received no drug all over the period of the experiment. Group 3: High cholesterol diet (HCD) + curcumin treated group: Rats fed with HCD + administrated with curcumin (200 mg/kg, body weight/day orally) after two weeks from the onset of the experiment (induction of hypercholesterolemia). Group 4: Normal curcumin group: Rats fed with normal diet + administrated with curcumin (200 mg/kg, body weight/day orally) after two weeks from the onset of the experiment.

2.5. Sampling:

Random blood sample specimens were collected from all animals groups (control and experimental groups) three times along the duration of experiment after 2 weeks, 4 weeks and 6 weeks from the onset of treatment with curcumin.

2.5.1. Blood samples:

Blood samples for serum separation were collected by ocular vein puncture in dry, clean, and screw capped tubes and serum were separated by centrifugation at 2500

r.p.m for 15 minutes. Serum was separated by automatic pipette and received in dry sterile samples tube and kept in a deep freeze at -20ºC until used for subsequent biochemical analysis .All sera were analyzed for total cholesterol (TC), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), phospholipid, apolipoprotein A (apo A), apolipoprotein B (apo B), Lipoprotein a Lp(a), homocysteine and endotheline-1 (ET-1).

2.6. Biochemical analysis:

Serum total cholesterol (TC), triacylglycerol (TAG), high density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), phospholipid, apolipoprotein A (apo A), apolipoprotein B (apo B), Lipoprotein a Lp(a), homocysteine and endotheline-1 (ET-1) concentration were analyzed according to the methods described by Ellefson and Caraway, (1976); Stein, (1987); National cholesterol Education program Recommendation for measurement of High –density Lipoprotein Cholesterol, (1995); Friedewald et al., (1972); Bauer, (1982); Takayama et al., (1977); Rat Apolipoprotein A1 (APOA1) ELISA (Kamiya Biomedical Company, Cat. No. KT-7354); Rat Apolipoprotein B (APO B) ELISA (Kamiya Biomedical Company, Cat. No. KT- 7394); Rat Lp-a (Lipoprotein a) ELISA Kit (Elabscience, Catalog No: E-EL-R0591); Rat Homocysteine (Hcy) ELISA Kit (Catalog No.CSB-E13376r); Rat Endothelin-1 (EDN1) ELISA (Kamiya Biomedical Company.Cat.No.KT-14033).

2.7. Statistical analysis:

The obtained data were statistically analyzed by one-way analysis of variance (ANOVA) followed by the Duncan multiple test. All


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analyses were performed using the statistical package for social science (SPSS, 13.0 software, 2009), values of P<0.05 were considered to be significant.

3. RESULTS

3.1. Effect of curcumin administration on serum total cholesterol, triacylglycerol and phospholipids concentration in normal and high cholesterol fed male rats (mg/dl):

The obtained results in table (1) revealed that, a non-significant increase in serum TC concentration after 2 week this increase became significant after 4,6 week, associated with a significant increase in serum TAC and phospholipids concentration was observed in cholesterol fed rats all over the period of the experiments when compared with rats fed normal control diet. Curcumin treatment in rats fed high cholesterol diet resulted in non-significant increase in serum TC level after two weeks, a significant decrease in serum TC after four and sex weeks of the experiments as compared to untreated cholesterol -fed rats. Also, curcumin treatment resulted in a significant decrease in serum TAC level all over the periods of the experiments as compared to untreated cholesterol -fed rats. Curcumin treatment in rats fed high cholesterol diet resulted in a non-significant decrease in serum phospholipids level after two and four weeks of the experiments as compared to untreated cholesterol -fed rats, associated with a significant decrease in serum phospholipids level after six weeks of the experiments as compared to untreated cholesterol -fed rats.

3.2. Effect of curcumin administration on serum HDL-c, LDL-c and VLDL-c concentration in normal and high cholesterol fed male rats (mg/dl):

The obtained results in table (2) revealed that, a significant increase in serum LDL-c and

VLDL-c concentration. On the other hand, a significant decrease in serum HDL-c concentration was observed in cholesterol fed rats all over the period of the experiments when compared with rats fed normal control diet. Curcumin treatment resulted in a significant decrease in serum LDL-c (2- weeks non- significant) and VLDL-c level all over the periods of the experiments as compared to untreated cholesterol -fed rats. On the other hand, Curcumin treatment resulted in a non-significant increase in serum HDL-c level all over the period of the experiments as compared to untreated cholesterol -fed rats. Also, curcumin resulted in a significant increase in serum HDL-c level after two weeks of the experiments as compared to untreated cholesterol -fed rats.

3.3. Effect of curcumin administration on serum Lipo A, Apo A and Apo B concentration in normal and high cholesterol fed male rats (mg/dl):

The obtained results in table (3) revealed that, a significant increase in serum lipoprotein A and Apo B concentration, meanwhile, a significant decrease in serum Apo A was observed in cholesterol fed rats all over the period of the experiments when compared with rats fed normal control diet. Curcumin treatment in rats fed high cholesterol diet resulted in a significant decrease in serum Lipoprotein A and Apo B level, meanwhile, a non-significant increase in serum Apo A all over the period of the experiments as compared to untreated cholesterol -fed rats.

3.4. Effect of curcumin administration on serum Endothelin-1 and Homocysteine concentration in normal and high cholesterol fed male rats (mg/dl):

The obtained results in table (4) revealed that, a non-significant increase in serum endothelin-1 and homocysteine concentration was observed in cholesterol fed


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rats after two weeks of the experiment when compared with rats fed normal control diet. This increase became significant after four and six weeks of experimental. Curcumin treatment in rats fed high cholesterol diet resulted in a significant decrease in serum Endothelin-1 level all over

the period of the experiments as compared to untreated cholesterol -fed rats. In addition to, a non-significant decrease in serum Homocysteine level after two and six weeks associated with a significant decrease after four weeks of the experiment as compared to untreated cholesterol -fed rats.

Table (1): Effect of curcumin administration on serum total cholesterol, triglycerides and phospholipids concentration in normal and high cholesterol fed male rats (mg/dl)

Experimental groups

Total Cholesterol (mg/dl) Triacylglycerols (mg/dl) phospholipids (mg/dl)

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

Normal control 67.04±8.27a

78.42±0.42b

85.77±2.43b

85.89±2.65b

88.14±2.45b,c

76.52±11.95b

66.56±1.07c

67.95±5.42b

79.13±6.31c

High cholesterol diet 74.94±3.70a

96.89±10.39a

111.68±5.98a

117.62±6.00a

121.01±9.09a

111.59±7.71a

111.82±15.74a

98.47±11.67a

120.59±1.67a

curcumin treated 88.22±6.85a

71.78±5.94b,c

68.97±5.04c

72.26±14.52b

78.59±5.63b,c

69.99±7.94b

95.57±12.34a,

b

90.27±9.99a,b

75.24±3.39c

curcumin Normal 68.01±8.82a

56.99±3.79c

65.40±5.62c

76.30±7.05b

77.77±5.88b,c

76.52±7.82b

64.44±2.55c

70.73±4.29a,b

68.01±4.81c

Data are presented as (Mean ± S.E). S.E = Standard error. Mean values with different superscript letters in the same column are significantly different at (P≤0.05).

Table (2): Effect of curcumin administration on serum HDL-c, LDL-c and VLDL-c concentration in normal and high cholesterol fed male rats (mg/dl)

Experimental groups

VLDL-C (mg/dl) LDL-C (mg/dl) HDL-C (mg/dl)

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

Normal control 39.62±0.75a,b

47.29±1.05a

49.95±2.44a

7.05±2.09 c

13.51±0.81b

20.51±2.29b

17.18±0.35b

17.63±0.49b,c

15.31±2.39b

High cholesterol diet 32.93±1.43b

34.14±0.94b

37.18±0.21b

35.21±8.65 a

38.55±8.29a

51.94±4.67a

23.52±1.20a

24.20±1.82a

22.32±1.54a

curcumin treated 42.51±2.36a

38.69±5.27a,b

38.78±1.07b

31.26±8.14 a,b

17.37±3.37b

16.19±5.25b

14.45±2.90b

15.71±1.12b,c

14.00±1.59b

curcumin Normal 43.92±2.51a

35.31±1.04b

33.05±4.66b

15.23±3.75b,c

9.47±2.24b

17.05±1.92b

14.38±0.96b

15.55±1.18b,c

15.30±1.56b



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Table (3): Effect of curcumin administration on serum Lipo A, Apo A and Apo B concentration in normal and high cholesterol fed male rats (mg/dl)

Experimental groups

Lipo a ApoA1 Apo B

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

2 weeks

4 weeks

6 weeks

Normal control 3.03±0.25 b,c

3.09±0.07 b

2.26±0.24 b

17.74±1.50a

20.45±1.38a

16.68±1.01a

0.71±0.10b

0.74±0.09b

0.64±0.03b,c

High cholesterol diet 4.02±0.18 a

4.12±0.39 a

4.79±0.30 a

10.56±1.231b

13.97±1.88b

12.37±1.22c

1.13±0.09a

1.16±0.05a

1.05±0.08a

curcumin treated 2.35±0.20 d

2.40±0.21 b

2.88±0.51 b

12.63±2.26b

14.41±1.80b

14.07±0.91a,b,

c

0.75±0.04b

0.76±0.04b

0.65±0.07b,c

curcumin Normal 2.90±0.19 b

2.84±0.08 b

2.60±0.15 b

17.31±1.17a

17.54±0.52a,b

15.73±0.60a,b

0.65±0.04b

0.77±0.15b

0.75±0.06b,c

Data are presented as (Mean ± S.E). S.E = Standard error. Mean values with different superscript letters in the same column are significantly different at (P≤0.05)

Table (4): Effect of curcumin administration on serum Endothelin-1 and Homocysteine concentration in normal and high cholesterol fed male rats (mg/dl)

Experimental groups Endothelin-1 Homocysteine

2 weeks 4 weeks 6 weeks 2 weeks 4 weeks 6 weeks

Normal control 21.61±0.64a 18.17±0.64b 20.79±0.64b,c 0.88±0.08 a 1.09±0.34 c 0.67±0.16 c

High cholesterol diet 22.73±0.64a 25.73±0.64a 25.35±0.64a 1.42±0.09 a 2.20±0.11 a 1.68±0.14 a

curcumin treated 11.87±0.64d 15.99±0.64b 21.30±0.64b 1.30±0.16 a 1.54±0.02 b 1.32±0.21

a,b

curcumin Normal 16.45±0.64b 18.13±0.64b 17.32±0.64d 1.07±0.04 a 1.13±0.08 c 1.15±0.09

b,c


4. DISCUSSION

The obtained results demonstrated in (Table 1, 2) revealed that, a significant increase in lipid profile in high cholesterol diet group. Cholesterol-cholic acid feeding has often been used to raise cholesterol levels in plasma and tissues of experimental animals (Chen et al., 2004). It has been shown by other investigators that an increase in dietary cholesterol intake in animals led to

hypercholesterolemia (Kishida et al., 2002). The high levels of TAG in the present study may be due to inhibition of 7a-hydroxylase activity (Beigneux et al., 2002). Also, the high levels of LDL-C found in hypercholesterolemic rats, may be attributed to a down regulation in LDL receptors by cholesterol and saturated fatty acids included in the diet (Mustad et al., 1997), moreover, this increase in LDL-c level after high fat diet consumption might be explained via involvement of two enzymes namely


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cholesterol ester hydrolase and cholesterol ester synthetase. These enzymes balance the cholesterol levels in the blood. Hence, it is logical to assume that the elevation in plasma cholesterol is mediated through increased cholesterol turnover and influenced by the relative balance between cholesterol ester hydrolase and cholesterol ester synthetase activity. With increased esterifying activity (when cholesterol ester hydrolase: cholesterol ester synthetase is lowered) cholesterol will be predominantly in its ester form (as in LDL-c) and can lead to the development and progression of atherosclerosis (Shanmugasundaram et al., 1986). The obtained results demonstrated in (Table 1, 2) revealed that, curcumin in rats fed high cholesterol diet resulted in decrease of lipid profile. Curcumin might decrease absorption of cholesterol and increase the activity of cholesterol-7α-hydroxylase (Feng et al., 2010). This hypocholesterolemic effect of curcumin may be attributed to its stimulatory effect on hepatic cholesterol-7α-hydroxylase enzyme, an enzyme that regulates cholesterol catabolism (Babu and Srinivasan, 1997). Curcumin also reported to modulate (decrease) 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase enzyme activity to decrease serum and liver cholesterol, triglycerides and free fatty acid levels (Murugan and Pari, 2006). Moreover, Ramirez-Tortoza et al., (1999) found hypo-cholesterolemic effect in rabbits fed by a high-cholesterol diet. The mechanism is assumed through increased cholesterol excretion in the gall bladder together with decreased saturation of biliary cholesterol and increased fat excretion in the feces who reported that, oral administration of turmeric extract inhibits LDL oxidation and has hypocholesterolemic effect in rabbits with experimental atherosclerosis. In the present study, HDL-C levels were significantly increased in curcumin treated group this proves that curcumin not only regulate hyperlipidemia through decreased

blood cholesterol and triglyceride levels but it also enhance the levels of lipid removing cholesterol i.e. HDL-C in blood with increased Apo A I and paraoxonase enzyme activity (Jang et al., 2008). The obtained results demonstrated in (Table 3) revealed that, a significant increase in serum lipoprotein A and Apo B was observed in cholesterol fed rats all over the period of the experiments. In present study, increased level of Apo B on high cholesterol feeding diet may be due to decreased expression of LDL-receptor during hyper-cholesterolemia. Decreased level of LDL-receptor is responsible for decreased clearance of apoB along with LDL, so these apolipoproteins are accumulated in the body (Ouguerram et al., 2004). However, most of the studies suggested that one molecule of Apo B exists per lipoprotein particle, thus the quantity of Apo B in fasting plasma predicts the number of LDL and VLDL particles (Levinson and Wagner, 1992). Therefore, plasma Apo B levels maybe a better assay of the concentration of atherogenic lipoprotein particles than total or LDL cholesterol levels (Sniderman and Silberberg, 1990). Abnormalities in the Apo B metabolism are responsible for the generation of hypercholesterolemia and increased risk of coronary heart disease (Whitfield et al., 2004). Several mechanisms of Lp(a) participation in atherogenesis have been proposed. One of them consists in the direct deposition of that lipoprotein on arterial wall, similarly to that which happens with LDL and oxidized LDL. The fact that Lp(a) is more likely to undergo oxidation than LDL itself might facilitate uptake by macrophages via scavenger receptors (Argraves et al., 1997). That is the most universal mechanism of atherogenesis, in which macrophages ‘indulge themselves’ in the cholesterol from LDL, and eventually from Lp(a), transforming themselves into foam cells, precursors of atherosclerosis. Another pro-atherogenic mechanism of Lp(a)


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would relate to the inverse correlation between that lipoprotein levels and vascular reactivity, in which case the increase in Lp(a) plasma levels would induce endothelial dysfunction (Wu et al., 2004). Apo A plays a key role in the metabolism of HDL-cholesterol, which is esterified in the bloodstream by lecithin cholesterol acetyltransferase, using Apo A as a cofactor, and then returns to the liver for excretion as bile acids or redistribution to other tissues, since high levels of Apo A are accompanied by high concentrations of the oxidation-resistant HDL, Apo A is thought to be a marker of adequate anti-atherogenic defense. By contrast, apo B is associated with the LDL, which plays a central role in the uptake of cholesterol-rich LDL particles by peripheral tissues and liver. A high concentration of LDL (and therefore of apo B), is atherogenic, since it is ingested by macrophages, thus producing foamy cells (Hashimoto et al., 2000). LDL is also involved in other pathological processes such as up-regulation of adhesion molecule expression, attachment to endothelial cells, migration and subendothelial localization of macrophages, recruitment of smooth muscle cells and platelet activation, with resulting risk of thrombosis (Witting et al., 1999). As pointed out by Martens et al., (1999), oxidatively modified Apo B plays a central role in the above mechanisms, since it is the main macrophage proliferation inducing factor. The curcuma induced decrease of Apo B is interesting in relation to the above mentioned LDL-oxidation hypothesis of atherosclerosis according to which atheroma formation is linked to an increase in circulating Apo B (Chaput et al., 1999), as well as to current attempts to prevent or retard atherogenesis by antioxidant supplementation (Johnson, 1993). The clinical use of antioxidants in the prevention of the early stages of atherosclerosis and associated CVDs may be defended on the grounds that oxygen stress

appears to be involved not only in atherogenesis but also in a number of related risk factors and diseases such as hypercholesterolemia (Lavy et al., 1991). The obtained results demonstrated in (Table 4) revealed that, a marked increase in serum endothelin-1 and homocysteine concentration was observed in cholesterol fed rats. Horio et al., (1991) reported that, animal studies in rats fed a high-cholesterol diet have shown that circulating ET-1 levels and ET-1 immunoreactivity are increased in the epicardial coronary arteries and aortas of these animals before the development of atherosclerotic plaques. Oxidized LDLs have also been shown to increase ET-1 mRNA expression in cultured porcine and human aortic endothelial cells (Boulanger et al., 1992). Studies have indicated that LDL and oxLDL cholesterol stimulate the production of ET-1(Niemann et al., 2005). It has also been indicated that ET-1 stimulates the uptake of oxLDL in endothelial cells via stimulation of LDL receptor 1(LOX-1), mediated by ETB receptor (Morawietz et al., 2001). Similarly, ET-1 levels are elevated in patients with hypercholesterolemia, even in the absence of clinical cardiovascular disease (Mangiafico et al., 1996). Chronic homocysteinaemia also activates production of protein-1-mediated deregulation of endothelin-1 (ET-1), which is a strong vasoconstrictor and a key molecule involved in atherogenesis. Pro-oxidative states and hyper-homocysteinaemia also induce oxidation of LDL particles and the expression of lectin-type oxidized LDL receptor 1(LOX-1) on endothelial cell surfaces (Antoniades et al., 2009). These events induce foam cell formation and further promote atherogenesis. High plasma homocysteine levels have been linked to coronary artery disease (CAD) (Nygard et al., 1997). Curcumin treatment in rats fed high cholesterol diet associated with decrease in serum Homocysteine level These results are


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nearly similar to those recorded by Usharani et al., (2008) who reported that, Patients receiving 150 mg of curcumin twice daily showed an improvement of endothelial function and significant reductions in the levels of malondialdehyde, ET-1, IL-6, and TNF-α. Also, Ramaswami et al., (2004) showed that, curcumin blocks homocysteine (HE)-induced endothelial dysfunction in porcine coronary arteries. They found that curcumin could effectively block homocysteine- induced impairment of endothelium-dependent vasorelaxation, inhibit the homocysteine-induced epithelial nitric oxide synthase (NOS) expression, and block the effect of homocysteine on superoxide anion production. Conclusion: The curcumin administration produces potent anti-atherogenic and an effective treatment against hypercholesterolemia induced by high cholesterol diet in rats, since curcumin was able to ameliorate serum biochemical parameters, lipid profile, and endothelial function. We recommended that, administration of diet rich in the natural antioxidant is very important for protection of different body tissue, against oxidative stress or hypercholesterolemia and cardiac vascular disease and may be beneficial for patients who suffer from hyper-lipidemia, hypercholesterolemia and/or arteriosclerosis.

Acknowledgements

The authors are particularly grateful to the central lab and lab animal center, faculty of veterinary medicine, Benha University, Egypt, for assistance in laboratory tests and providing lab animals.

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.تاثیر الكركمین الخافض لدھون الدم في الفئران المصابھ بارتفاع الكولیستیرول

مجدى فؤاد عطیة حمادمحمد ، محمد رجاء رجب حسانین، یاقوت عبدالفتاح السنوسى ، سامي علي حسین جامعة بنھا -كلیة الطب البیطرى - الكیمیاء الحیویة قسم

الملخص العربي

أثیر ة تم تقییم الت دراس ذه ال دھون في على التغیرات كركمینلل العالجيفي ھ توي ال دم، أبولیبوبرتینفي مس أ -الیلین–ب ، اللیبوبرتین–،أبولیبوبروتین تین1-أ ، اندوس یس تحدث فیھا زیاده في دم1-، ھیموس ترول بالدم الفئران المس الكولیس

ترول.بال غنیة بعلیقة طویل مدى على تغذیتھا طریق عن ة عدد كولس تخدم ألجراء ھذه الدراس من ذكور 60ھذا وقد أسجرام وقد قسمت إلى أربع مجموعات متساویة 220-180من وأوزانھا أسبوع 16-12الفئران البیضاء أعمارھم تتراوح من

ابطة):اش رة جرذا وتم توزیعھا كاآلتي: المجموعة األولى: (المجموعة الض ھ عش تم تملت كل مجموعة على عدد خمسیة العلیقة على تھاتغذی اس أدویة واستخدمت كمجموعة ضابطة للمجموعات األخرى. المجموعة الثانیة: تجریعھا یتم ولم األس

ترول زیادة(المجموعة المحدث بھا تیرول ( الكولیس تیرول + %4بالدم): تم تغذیتھا بغذاء عالي الكولس حمض %1كولسابیع 8الكولیك) لمده تخدمت أس ابطة كمجموعة وأس . المجموعة الثالثة:( المجموعة التجریبیة المجموعات لكل إیجابیة ض

تیرول بالدم + الكركمین) تر عالیة بالعلیقة ذیتھم غ:تم ت المحدث بھا زیاده الكولس ن بجرعھ مع تجریعھا بالكركمی ولالكولسى بعد كجم من وزن الفئران1مجم لكل 200 بوعین ُمض . المجموعة الرابعة:(مجموعھ الكركمین التجربة بدایة منذ اس

یة العلیقة على تھاتغذی تمالطبیعھ): اس بعد كجم من وزن الفئران1مجم لكل 200ثم تم تجریعھا بالكركمین بجرعھ األسى بوعین ُمض ابیع 6، 4، 2من جمیع الفئران على ثالث فترات بعد الدم عینات جمعت. التجربة بدایة منذ اس من بدایة أسترول البیوكیمیائیة التحالیل إلجراء العالج ریدات للكولیس ةو لكثافةا عالیة الدھنیة البروتینات و الثالثیة والجلیس منخفضدیدة و الكثافة فولیبد و أب الكثافة إنخفاض ش یلین–ب و اللیبوبرتین–و أبولیبوبروتین أ-ولیبوبرتینو الفوس 1-أ و اندوس

تین یس افھ الي ھیموس فرت نتائج التحلیل البیوكیمیائى عن وجود 1-باالض تیمعنویھ فى كال من ا زیادة. وقد أس و روللكولیسریدات ةو الثالثیة الجلیس دیدة و الكثافة منخفض فولیبد الكثافة إنخفاض ش أ و –اللیبوبرتین ب و–و أبولیبوبروتین و الفوس

یلین تین 1-اندوس یس الكثافة و عالیة الدھنیة في البروتینات، من جھة اخرى اظھرت النتائج نقص معنوي 1-و ھیموس لكولیسترولا زیادةأ فى المجموعھ المحدث بھا زیاده الكولیستیرول. كما أن نتائج مجامیع الفئران المحدث بھا -أبولیبوبرتین

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